Alexander miller



2 Sheets-Sheet"'1.

(No Model.)

A. MILLER.

EVAPORATING APPARATUS.

No. 428,281. Patented May 20, 1890.

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a/fiZ 2 SheetsSheet 2.

(No Model.)

A. MILLER.

. EVAPORATING'APPARATUS.

Patented May 20,1890.

we cams puns co, monrunm, WASNINGYON, a. c.

UNITED STATES PATENT OFFICE.

ALEXANDER MILLER, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO ROBERT DEELEY, OF SAME PLACE.

EVAPO RATING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 428,281, dated May 20, 1890.

Application filed July 20, 1888. $erial No. 280,499- (No model.)

.To'aZZ whom it may concern:

Be it known that I, ALEXANDER MILLER, of the city and county of New York, in the State of New York, have invented a new and useful Improvement in Evaporating Apparatus, ofwhich the following is a specification. 7

My invention" relates in part to all evaporating apparatus in which the evaporatingpaus are provided with contained heatingbelts or steam-chambers, and in part only to apparatus in which a partial vacuum is maintained in the pans.

The improvement will be hereinafter fully described, and its novelty will be pointed out in the claims.

In the drawings, Figure 1 represents a side elevation View of an evaporating apparatus embodying my improvement. Fig. 2 represents a side elevation part sectional view of the same apparatus at right angles to the view given in Fig. 1. Fig. 3 represents a horizontal sectional view of the heating-belt or steam-chamber on line at w of Fig. 2, in which the heating belt or chamber is divided bya curb or partition. into two concentric compartments, circular in outline, of horizontal section. Fig. 4 represents a horizontal sectional view of a modification of the heating-belt represented in Fig. 3, in which the inner or contained compartment is located at one side of the center of the belt.

Like letters of reference indicate similar parts mall the drawings. I

A is an evaporating-pan, which in this example of my invention is of the variety known as a vacuum-pan, a partial vacuum being maintained therein when in operation. The shell a is represented of cast-iron lined with a copper lining b. The shell and lining are represented as formed in parts or sections united with horizontal flanged air-tight joints 0 c c. The lining b is preferably of thin metal, and the flanges of its several parts are turned over upon and securely held between the flanges of the cast-iron shell. The object of the copper lining is to protect the cast-iron shell from the corrosive effects of the contained liquid. In the drawings, Fig. 2, only that part of the casing above the heating-belt is'represented as having a copper lining; but

such a lining might also beapplied to the part below the said belt. To prevent a collapse of the thin metal lining from the expansion of air leaking through the shell or unavoidably left between the shell and the lining, I connect the space between the shell and lining with the condenser in any convenient manner, as by suitable pipes passing into and through the shell. In Fig. 2, g g 9 represent such pipes, one of which is provided for each belt or section of the lined part of the shell, and, communicates through the larger pipe 72 with the condenser 13, thereby maintaining a vacuum between the casing a and lining 1) equal to that of the interior of the vacuum-pan.

C is the vapor-pipe through which the vapors from the vacuum-pan pass into the condenser B, which may be,'and, though not represented in detail, is here supposed to be, what dry-vacuum w is commonly known as-the condenser. V

is the condenser leg-pipe, through which the water of condensation descends to the leg-pipe seal-tankj, whence it passes away to drainage basin or sewer.

76 7c are strong lugs projecting from the pan and resting upon the floor-timbers Z l for supporting the pan and attachments.

That part of the vacuum-pan represented in the drawings which extends below the heating-surface has the form of an elongated funnel, having at its lower end a leg of considerable length for providing a comparatively cool and quiet body of liquid to facilitate the separation and deposit of the solid precipitate, and terminates at the bottom in a pit or pocket m. s

z z are lugs resting upon supporting-timbers ll.

2 is a dischargepipe, through which the I pan, where the evaporating process is carried for the purpose of preventing overflow from' the opening at which the discharging-elevator is introduced, but is for thepurpose of preventing the air from the surrounding atmosphere from entering the vacuum-pan through said opening and vitiating the vacuum therein. Therefore it is necessary onlythat the hollow column should in my invention extend to such a height that the col umn of liquid therein and the pressure of the atmosphere thereon should counterbalance the column of liquid in the pan and the pressure of'the vapor in the pan, and it is only'in order that there may not be any accidental overflow over the top of the said col-' umnin ease of thevacuum in the pan being broken that the said column should extend upward to a level somewhat above that to which'the liquid rises in the pan, and I have for this reason represented it as extended to such a height;

D is a heating belt or chamber contained within the evaporating-pan, in which steam is employed to evaporate the liquid alsocontained therein.- 111 this example of my.in-

vention the heating-belt D is provided with numerous small tubes d, the extremities of which are expanded into an upper and a lower head-plate. The tubes d converge toward the lower head-plate e and diverge toward the upper head-plate f. The distance between the upper ends of the tubes (1 being greater than that between the lower ends of the same tubes, the steam or vapor produced by the contact of the liquid with the heated tubes d will pass upward through the body of the liquid above the head-plate f of the belt with greater freedom than if the tubes were parallel onewithanother. To facilitate the construction of a heating-belt D, in which the tubesd diverge and converge, as ELbOX'O set forth, it is desirable that each tube be perpendicular to both the head-plates at the parts where it meets the same. This 1 accomplish by giving convexity to both headplatesin the same directionas, for example, as indicated in Fig. 2by giving to the plate f the form of a part of the surface of a sphere, and giving to the plate 6 the form of a corresponding part of the surface of a smaller concentric sphere.

E E E are comparatively large tubes flush with the upper head-plate f, and, like the tubes (1, converging toward the lower headplate. They are secured in a suitable manner, as by flanges, to the head-plates, and extend below the bottom head any required distance, for the purpose of returning the liquid passing up through the small tubes 61 down again below the heating-belt, carrying with it the solid matter freed from the liquid by the escape of vapor down a distance below the head into the comparatively quiet and cooler liquid, where it can fall freely into the discharging apparatus. These large tubes E E E are preferably placed in the center of the heating-pan and equidistant from that center. The said tubes are preferably tapered, the larger ends being upward.

In this example of my invention the heating-belt is divided into compartments, which may besmrerally-supplied with live or expanded steam independently of each other. The compartments in this example are two in number and are of unequal size or capacity, and the live and expanded steam may be taken into either, according to thecomparative quantities of either or both kinds of steam that maybe at any time available. The compartments may have any suitable form-as, for example, they may be, as indicated in the drawings, circular in horizontal section-and the compartments may-be concentric, as represented in Figs. 2 and 3, or the contained compartment may be at one side of the interior of the other.

13 and p are the curbs or partitions by which the belt or chamber is divided into compartments.

q and q are the inlet steam-pipes communicating with the contained compartment.

r is an inlet steam-belt, formed in this ex ample by. an annular enlargement of the belt ;or section of the cast-iron casing a, which forms the outer Walls of the steam chamber or belt D of the drawings. The steam passes from the inlet-belt 0 into the heating belt or chamber through numerous slits oropen- Jugs s s.

F is a heater, through which the cold liquid to be evaporated passes before entering the pan.

the liquid enters the heater.

u is a pipe by which the same liquid is con- :ducted from the heater into the vacuum-pan. o is a pipe branching flOlIl' the vapor-pipe before it enters the condenser to convey a partof the vapor into the heater for the purpose of heating the liquid toa certain degree before it enters the pan.

w is an exhaust-pipe, through which the t is the cold-liqnid-inlet pipe, through which IIO level sufficiently below the bottom head of the heating-belt to allow the waters of condensation to flow through the pipe 2. In this example of my invention the pipe. .2 is provided with a stop-cock .2 operated by hand. The stop-cock .2 may be left slightly openjust open enough to allow the Waters of condensation to drain off into the heater, but not enough to allow steam to pass through and vitiate the vacuum in the heater. In practice it will be found convenient to let the stop-cock 5 remain slightly less open than as above set forth, and when the water accumulates in the heating-belt to open wide the cock 2 and let the accumulated water run into the heater. After thus discharging the water the stop-cock can be again partially closed and allowed to remain slightly open, as above set forth. To provide for drawing off air that may accumulate within the upper part of the heating-belt, I introduce a pipe g through the side of the pan into the interior of the heating belt or chamber terminating immediately beneath the highest part of the dome-shaped upper head-plate f and communicating with the interior of the condenser B. In this example, for convenience, the pipe 9 enters the lower end of pipe 71.. The pipe g is provided with an easily-accessible stopcock 9 By opening the stop-cock 9 communication may be made and broken at will between the interior of the heating-belt and the condenser and any air from time to time accumulating under the upper head f may thereby be drawn ofi into the condenser E; or the cock g may remain very slightly open all the time for the escape of air.

lVhat I claim as my invention, and desire to secure by Letters Patent, is-

1. In a heating-belt for an evaporating-pan,

vapor-pipe, and means in connection with the vapor-pipe for maintaining a partial vacuum in the pan, of a heater, abranch pipe leading from the vapor-pipe to the heater, apparatus for maintaining in the heater a vacuum slightly greater than that of the vacuum-pan to induce a current from the vapor-pipe to the heater, a pipe for supplying liquid to the heater, and a pipe for conducting liquid from the heater to the vacuum-pan, substantially as set forth.

4. In an evaporating apparatus, the combination, with a vacuum-pan provided with a contained heating-belt for steam, of a heater in which a vacuum slightly greater than that of the pan or its condenser may be maintained to induce a current from the vaporpipe through the heater, the heater being placed a certain distance below the bottom head of the heating-belt to receive the water of condensation from the belt, a branch pipe from the vapor-pipe between the pan and condenser to convey a part of the vapor into the heater, a passage for conducting the water of condensation from the heating-belt to the heater, and pipes for conducting the liquid to be evaporated into the heater, and from the heater into the evaporating-pan above the heating belt, and means, substantially as described, for drawing ofli the water of condensation from the heater, all substantially as described and set forth.

5. In an evaporating apparatus, a vacuumpan having a shell and a lining, the space be tween the shell and lining being connected with the condenser by pipes passing into and through the shell for maintaining a vacuum between it and the lining, substantially as herein described and set forth.

ALEX. MILLER.

IVitnesses:

FREDK. HAYNES, HENRY J MCBRIDE. 

